feat: multimodal image clients, workspaces, Tushare skill, test fixes

- Replace monolithic image_message_client with HTTP/OCR/legacy modules; tighten OpenAI transport + tool schemas for multimodal downgrade to OCR specialist path.
- Add image/stock workspace prompts (META/SOUL/ROLE_SYSTEM); register experts; tweak specialist agent/direct loop/query_image_attachment.
- Add bundled runtime/skills/tushare-finance (references, api_client, SKILL metadata).
- Document OCR-related env vars; admin chat tweaks; README; weixin_install Ensure-OfficialPluginRuntimeDeps helper.
- Tests: multimodal downgrade + OCR coverage, strict tool pairing in attachment replay guard, workspace contract skips _internal/_system dirs, router/trace/prompt guards.

Co-authored-by: Cursor <cursoragent@cursor.com>

runtime/skills/tushare-finance/reference/接口文档/数据索引.md

@@ -0,0 +1,20 @@
+# 数据索引
+
+**文档ID**: 209
+**原始链接**: https://tushare.pro/document/2?doc_id=209
+
+---
+
+## Tushare数据索引
+
+股票基础
+
+分钟行情日线行情周线行情月线行情复权行情复权因子每日涨跌停价格每日涨跌停统计停复牌交易日历
+
+总市值流通市值总股本流通股本自由流通股本换手率量比股息率市盈率（PE）市净率市销率均线
+
+上市公司基本信息公司高管管理层持股新股发行沪港通成分股深港通成分股历史曾用名
+
+财务数据
+
+利润表资产负债表现金流量表业绩快报业绩预告主营业务构成分红送股财务审计报告财报预披露日期表